In an earlier apparatus for this purpose, all of the nozzle holes make up a single nozzle hole group. This can involve up to 120 nozzle holes. The spinning pumps service this group jointly and are jointly serviced by a single regulator, i.e. the pumps feed a single spinning head or spinneret.
From time to time the diameters of the individual monofilaments are measured in the laboratory. An attendant then feeds the measured values of diameter into the regulator in an appropriate manner.
Thus the attendant and the laboratory worker are needed to close the regulating cycle.
The regulation procedure is influenced considerably by the subjective estimate of this individual. Furthermore this procedure causes a significant delay or control-response lag time. This delay, the errors it causes, as well as the deviations in the diameters of the bundle of monofilaments, can be quite severe.